Species of the genus Diaporthe/Phomopsis are endophytes on a very
wide range of hosts and can be present as pathogens or saprophytes. Species of
this genus cause a complex of diseases on the stem and seeds of soybean (Glycine
max (L.) Merr.) and therefore belong to a group of important parasites of this plant.
Diaporthe phaseolorum and Phomopsis longicolla were described as soybean
pathogens. The first species includes three varieties: D. phaseolorum var. sojae, D.
phaseolorum var. caulivora and D. phaseolorum var. meridionalis. Although several
studies have extensively described the morphological and culture characteristics of
these pathogens, their taxonomy has not fully been defined. The greatest
taxonomic confusion is related to D. phaseolorum var. sojae, because this variety
expressed variability of morphological characteristics. Since morphological
variability of D. phaseolorum var. sojae was also observed in isolates from Serbia,
there were needs for detailed examinations in order

to exactly determine which
Diaporthe/Phomopsis species are present on soybean in Serbia. By comparison of
morphological, molecular and pathogenic data seven Diaporthe/Phomopsis species
were identified. Besides the known parasites, D. neotheicola, D. eres, D. viticola and
unidentified group Phomopsis sp. 9 were also detected on soybean seeds.
Identification and phylogenetic grouping was performed based on sequences of
ITS region and parts of LSU and TEF1-α genes. In order to find faster ways of
detection and identification, ITS sequences of the studied species were used for the
virtual digestion with restriction enzymes AluI, RsaI, HhaI, MseI, and StyI. Since
different molecular profiles were generated for each studied species, it was
concluded that PCR-RFLP technique can potentially be a useful method for rapid
and reliable identification of Diaporthe/Phomopsis species that occur on soybean.
By studying morphological characteristics of the identified species, it was found
that the dimensions of reproductive organs overlapping, but also that they vary
between isolates within a species, as well as within the isolates. Based on this, it
was concluded that dimensions of reproductive organs are not reliable parameters
for identification of Diaporthe/Phomopsis species isolated from soybeans...